EPI-NEWS NATIONAL SURVEILLANCE OF COMMUNICABLE DISEASES Editor: Tove Rønne Statens Serum Institut - 5 Artillerivej - 2300 S - Tel.: +45 3268 3268 - Fax: +45 3268 3868 - E-mail: [email protected] - Website: www.ssi.dk ISSN: 1396-4798

No. 20, 2000

TICK-BORNE ENCEPHALITIS IN tion before stays in . Vac- It is noteworthy that 16 of the pati- BORNHOLM cination is, however, recommended ents were adults; the median age During the past week the Depart- for prolonged stationing in known was 27 years, ranging from 0 to 53 ment of Epidemiology has had many endemic areas (see suggested vacci- years. In comparison, enterovirus enquiries about tick-borne or Central nations for foreign travel, EPI-NEWS infection was only demonstrated in European encephalitis (TBE) on the 17-18/99). The vaccine is initially gi- 3-6 patients during the same period island of Bornholm. The disease is ven three times in the course of the of 1998 and 1999, all of these being caused by a flavivirus that can be first year and then every third year. small children. Enterovirus infections transmitted by woodland ticks. The (K. Kristiansen, MOH, Bornholm show a marked seasonal variation, aetiology, symptoms and geographi- County, P. Andersen, Dept. of Epi- most infections occurring during the cal distribution of the disease were demiology) summer and autumn. Illness is seen described in EPI-NEWS 33/99. Inve- chiefly in children, but certain types stigations in the late 1950’s found INFLUENZA 1999/2000 of enterovirus appear at longer inter- TBE virus in Bornholm but not in the During this season between 73 and vals and can thus give rise to out- rest of Denmark. In Bornholm 1.4% 110 general practitioners participat- breaks that also affect adults. The of blood donors and 30% of forestry ed in the weekly sentinel surveil- current outbreak is probably caused workers had antibodies indicating lance of influenza-like illness. Sur- by echovirus 30, as this type of virus previous TBE infection. As no syste- veillance restarted in week 36/99. has so far been identified by isolation matic search for TBE has since been The regular reports indicated spo- and typing from four patients. undertaken in Bornholm, the current radic disease activity up to week 52, Echovirus 30 is among the entero- occurrence is unknown. Five cases when activity peaked, representing viruses most frequently described as were diagnosed in 1999, three of 4.8% of the sentinel physicians’ total causing encephalitis/meningitis in which were described in EPI-NEWS consultations. Activity then remained both children and adults. The diag- 33/99. New investigations are now greater than expected for the time of nosis of acute enterovirus infection is being planned to elucidate the oc- year, at 2.3-4.0% of consultations, nowadays performed by PCR de- currence of TBE. The results of these until week 8, after which it again monstration of virus in cerebrospinal will probably be available within declined to sporadic levels. Repor- fluid, nasopharyngeal secretions and about a year. ting for this season ended in week serum. Typing, however, requires 17. There has thus been no real in- isolation of the virus in cell culture. Risk of illness fluenza epidemic during this season. Unfortunately, there is often too little There are no grounds for supposing During the same period, the Influen- virus in the above-mentioned speci- that the occurrence of TBE in Born- za Laboratory examined a total of mens to permit isolation. In cases of holm has appreciably changed over 231 secretion specimens for influen- suspected or confirmed enterovirus the last many years. The vast major- za virus, 181 of which had been sent infection, it is therefore recommen- ity of people infected with TBE virus in by sentinel physicians. From the ded to include a faecal specimen for develop no symptoms. Advancing latter specimens 42 influenza A virus isolation. Enteroviruses replica- age increases the risk of serious, (H3N2) viral strains were isolated. te in the intestine and are excreted in chronic sequelae. The mortality in Six such strains and an H1N1 strain the faeces for 1-2 months. patients admitted to hospital is about were isolated from the other speci- (B. Böttiger, D.S. Hansen, Dept. of 1%. A past TBE infection, whether mens. All the H3N2 strains were Virology) clinical or subclinical, induces life- typed as A/Sydney/5/97- or A/Mos- long immunity. cow/10/99-like viruses. The H1N1 ANTHRAX IN NORWAY strain was typed as A/Johannesburg The Norwegian State Public Health Prevention /82/96-like virus. The strains that Institute has reported a bacteriologi- The risk of tick bites can be reduced were circulating in Denmark during cally confirmed, fatal case of anthrax by using boots, long trousers and the past season were thus, like those in a Norwegian i.v. drug user. There long-sleeved upper garments. After in neighbouring countries, closely may be a further case in another stays in areas where ticks are com- related to the strains used in the drug addict, which raises the possi- mon, the skin should be inspected, 99/00 influenza vaccine. bility that contaminated heroin could especially in children, and a bath (P.C. Grauballe, Influenza Lab., be the source of infection. Pending taken. This removes many ticks, S. Samuelsson, Dept. of Epidemiol.) results of further investigations, it is which usually crawl around for some advisable to be especially alert to time before settling to bite. Clothes ENTEROVIRAL MENINGITIS signs of the disease in i.v. drug users. should also be inspected, including In March and April, the Department This applies to soft tissue and skin the seam-side; pale clothing makes it of Virology found enterovirus in 33 infections associated with injection easier to spot the ticks. Ticks that patients, considerably more than sites, or signs of systemic infection in have bitten fast are removed with the usual for the time of year. In 25 pa- drug addicts. Any further informati- fingers or pincers. tients, enterovirus was demonstrated on will appear on Statens Serum in cerebrospinal fluid, and 17 of the- Institut’s website, under “News”. Vaccination se patients were stated to have cli- (P. Andersen, T. Rønne, Dept. of There are no data giving current nical meningitis. The patients were Epidemiology) support for recommending vaccina- distributed throughout the country. 17 May 2000 Patients with laboratory-diagnosed RSV or rotavirus infections, 2000

February March April RSV Rota RSV Rota RSV Rota

455 44 115 52 28 69

Reported from the following Clinical Microbiology Departments: Aalborg Hospital (South), Municipal Hospital, Herning Central Hospital, Hvidovre Hospital, Odense University Hospital, Slagelse Central Hospital, Viborg Hospital, and the Department of Virology, Statens Serum Institut.

(Dept. of Epidemiology)

ERRATUM / HEPATITIS A 1999 The incidence of West County in Table 2 in the annual report on hepa- titis A was not correct, EPI-NEWS 18/00. Here is the corrected table.

Table 2. Notified cases of hepatitis A by county, with incidence per 100.000, 1999 1998 in ( ) Incidence County No. 1999 (1998) Cph. Municip. 15 3.1 (7.2) Frb. Municip. 2 2.2 (2.2) Cph. County 19 3.1 (4.3) Frederiksborg 12 3.3 (1.1) 7 3.0 (0.9) West Zealand 8 2.7 (1.0) Storstrøm 0 - (0.8) Bornholm 1 2.2 - Funen 4 0.8 (0.6) South Jutland 3 1.2 (0.4) Ribe 1 0.4 (0.9) Vejle 2 0.6 (0.3) Ringkøbing 6 2.2 (0.7) Aarhus 6 0.9 - Viborg 0-- North Jutland 4 0.8 (0.2) Total 90 1.7 (1.6)

(Dept. of Epidemiology)